This invention consists chiefly in the combination with a rotating mandrel–whose form is that of a single cone or frustum of a cone–of two or mora pressing rollers, arranged and operating in such a manner as to coil a piece of wire of any length in the form of a continuous series of truncated cones, having their bases in alternate opposite directions. The wire thus coiled only requires to be cut apart, ",t the union of' the bases of thE; several coniform portions of the coil, to produce a number of dO"ll.le or single conical springs, such as are used for upholstery, and other purposes. This is the invention of James Harrison, Jr., of this city. It has just been patented in Great Britain, and was patented in the United States January 27, 1857.
This article was originally published with the title "Manufacturing Coiled Springs" in Scientific American 13, 11, 84 (November 1857)